ksupp function

Kernel support estimate

Kernel support estimate for 2 and 3-dimensional data.

ksupp(fhat, cont=95, abs.cont, convex.hull=TRUE)

## S3 method for class 'ksupp'
plot(x, display="plot3D", ...)

Arguments

• fhat: object of class kde
• cont: percentage for contour level curve. Default is 95.
• abs.cont: absolute density estimate height for contour level curve
• convex.hull: flag to compute convex hull of contour level curve. Default is TRUE.
• x: object of class ksupp
• display: one of "plot3D", "rgl" (required for 3-d only)
• ...: other graphics parameters

Returns

A kernel support estimate is an object of class ksupp, i.e. a 2- or 3-column matrix which delimits the (convex hull of the) level set of the density estimate fhat.

Details

The kernel support estimate is the level set of the density estimate that exceeds the cont percent contour level. If this level set is a simply connected region, then this can suffice to be a conservative estimate of the density support. Otherwise, the convex hull of the level set is advised. For 2-d data, the convex hull is computed by chull; for 3-d data, it is computed by geometry::convhulln.

See Also

kde

Examples

data(grevillea)
fhat <- kde(x=grevillea)
fhat.supp <- ksupp(fhat)
plot(fhat, display="filled.contour", cont=seq(10,90,by=10))
plot(fhat, cont=95, add=TRUE, col=1)
plot(fhat.supp, lty=2)

data(iris)
fhat <- kde(x=iris[,1:3])
fhat.supp <- ksupp(fhat)
plot(fhat)
plot(fhat.supp, add=TRUE, col=3, alpha=0.1)